Add support for Functions

[Befrish]

• CheckedConsumer
• CheckedPredicate
• CheckedRunnable
• CheckedFunction0 - 8
• Function0 - 8

[jlink]

Since functional interfaces are supported by jqwik out of the box, what additional functionality could there be?

For example:

@Property
void testCheckedPredicate(@ForAll CheckedPredicate<String> predicate) throws Throwable {
	assertThat(predicate.test("hallo"), equalTo(predicate.test("hallo")));
	Statistics.collect(predicate.test("hallo"));
}

will succeed and output something like:

[Experiments:testCheckedPredicate] (1000) statistics = 
    true  (501) : 50 %
    false (499) : 50 %

[Befrish]

I will have a look at this

[Befrish]

@jlink What result do you expect? If I change it to java.util.function.Predicate. There are nearly the same result (about 50:50).